The ubiquitous and ancient ER membrane protein complex (EMC): tether or not?
The ubiquitous and ancient ER membrane protein complex (EMC): tether or not?
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DOI：
10.12688/f1000research.6944.1
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发表时间：
2015-01-01
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影响因子：
--
通讯作者：
Wideman, Jeremy G
中科院分区：
文献类型：
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作者：
Wideman, Jeremy G
最近发现的内质网（ER）膜蛋白复合物（EMC）与内质网相关降解（ERAD）、内质网与线粒体外膜之间的脂质转运和系结以及多道内质网膜蛋白的组装有关。EMC在动物和真菌中都有研究，但它在Opisthokont分支（动物+真菌+相关原生生物）之外的存在尚未得到证实。在这里，使用同源搜索算法，我表明EMC确实是一个古老的和保守的蛋白质复合物，存在于每一个主要的真核生物谱系。很少有生物完全失去了EMC，大多数生物，即使经过20亿年的真核生物进化，也保留了大多数复杂成员。我将酿酒酵母中的Sop4和YDR056C分别鉴定为Emc7和Emc10，这两个亚基之前被认为是动物特有的。该研究表明，EMC存在于最后的真核生物共同祖先（LECA）中，是真核细胞的一个极其重要的组成部分，尽管其主要功能尚不清楚。
The recently discovered endoplasmic reticulum (ER) membrane protein complex (EMC) has been implicated in ER-associated degradation (ERAD), lipid transport and tethering between the ER and mitochondrial outer membranes, and assembly of multipass ER-membrane proteins. The EMC has been studied in both animals and fungi but its presence outside the Opisthokont clade (animals + fungi + related protists) has not been demonstrated. Here, using homology-searching algorithms, I show that the EMC is truly an ancient and conserved protein complex, present in every major eukaryotic lineage. Very few organisms have completely lost the EMC, and most, even over 2 billion years of eukaryote evolution, have retained a majority of the complex members. I identify Sop4 and YDR056C in Saccharomyces cerevisiae as Emc7 and Emc10, respectively, subunits previously thought to be specific to animals. This study demonstrates that the EMC was present in the last eukaryote common ancestor (LECA) and is an extremely important component of eukaryotic cells even though its primary function remains elusive.